The present invention relates generally to vehicle service systems having a computer configured to receive information to be utilized in performing a vehicle service, and more particularly, to a vehicle service system, such as a vehicle wheel alignment system, which is configured to communicate with at least one electronic control unit on-board a vehicle undergoing a vehicle service procedure via a vehicle fault tolerant communications bus.
While the present inventions will be described herein in the general context of a vehicle wheel alignment system, those of ordinary skill in the art will recognize that the concepts, features, and inventive aspects described herein are applicable to a wide variety of vehicle service devices, such as tire changing systems, tire balancing systems, engine diagnostic systems, etc. which can benefit from an ability to exchange data with, and communicate with, vehicle components.
Traditional vehicle wheel alignment systems, such as shown in U.S. Pat. No. 4,381,548 to Grossman et al., herein incorporated by reference, utilize a computing device, typically a general purpose or IBM-PC compatible computer, configured with wheel alignment software, which is connected to one or more vehicle wheel alignment angle sensors. The computing device is configured with software to compute angular relationships of the vehicle wheel, as is described in U.S. Reissue Pat. No. 33,144 to Hunter, et al. herein incorporated by reference, and typically is in communication with a variety of conventional input and output devices, such as keyboards, pointing devices, printers, displays, and audio components. Traditional vehicle wheel alignment sensors comprise angle transducers, such as shown in U.S. Pat. No. 5,489,983 to McClenahan et al., herein incorporated by reference, which are mounted to the wheels of a vehicle undergoing an alignment service, but may comprise camera systems, such as shown in U.S. Pat. No. 5,870,315 to January, herein incorporated by reference, designed to observe either the wheels themselves or targets mounted to the wheels, and to generate images from which alignment angles may be determined by the computing device.
In prior art wheel alignment systems, the individual wheel alignment sensors are connected to the computing device by means of data communication cables. As the wheel alignment systems evolved, the data communication cables have been replaced by wireless communications technologies such as infrared and radio-frequency communication links, wherein the computing device serves as a controller, transmitting instructions to the individual wheel alignment sensors, and receiving wheel alignment information in response. To avoid conflicting communications, individual wireless wheel alignment sensors employ a passive communications system which transmits information to the computing device only in response to specific instructions received there from.
In addition to requiring information from individual wheel alignment sensors, a wheel alignment system or other vehicle service system computing device requires information identifying the type of sensors which it is utilizing, information related to the vehicle undergoing service, and information identifying the manner and format of any output provided to the operator or technician. These various pieces of information are traditionally entered into the computing device manually, via the conventional input devices such as the keyboard or mouse.
Emerging wireless communication technology has enabled devices and appliances to interconnect in the form of mobile and amorphous networks capable of continually reconfiguring as elements are added and removed. Communication technology allows easy connection between devices and components, such as smart handheld devices and stand-alone equipment (i.e. general purpose computers to peripherals, etc) without the restrictions of cables or wires. Devices employing a wireless communications protocol can connect with multiple similarly configured devices located within a close proximity, forming a high-speed data network. These wireless communications protocols include user authentication, data encryption and data hopping facilities to protect privacy and to automatically prevent signal interference and loss.
Additional advancements have been made in the incorporation of electronic control units and systems in automotive vehicles such as passenger cars and light trucks. Automotive vehicles have evolved from including a single electronic control unit configured to perform engine management applications to complex systems incorporating fifty or more separate electronic control units which monitor, regulate, and control all aspects of automotive vehicle electronic systems. These systems may include, for example, engine management, fuel regulation, exhaust gas monitoring, passenger compartment climate control, lights, anti-lock braking systems, power windows and locks, and vehicle alarm systems. Additional advances in automotive vehicles have led to the proliferation of “by-wire” systems in which vehicle components previously controlled directly by a mechanical linkage are replaced by systems incorporating one or more actuating elements which are responsive to electronic signals received from an operator.
An example of a “by-wire” system is a “steer-by-wire” system in which the vehicle steering wheel is no longer mechanically coupled to the vehicle wheel steering mechanisms, such as shown in U.S. Patent Application Publication No. 2004/0236487 A1 to Yao et al. With a “steer-by-wire” system, movement of a vehicle steering device is detected by sensors, and corresponding signals are relayed to a vehicle steering device control unit. The steering device control unit in turn, determines an appropriate degree of turn to impart on the vehicle wheels to achieve the desired vehicle steering, given the vehicle's current operating conditions, and provides corresponding control signals to vehicle wheel steering actuators. One advantage of a steer-by-wire system is the ability of the steering device control unit to provide an optimal steering of the vehicle wheels for different vehicle operating conditions, for example, altering the sensitivity of the vehicle steering system based on the vehicle's ground speed.
Additional examples of “by-wire” systems include brake-by-wire systems, throttle-by-wire, shift-by-wire, and suspension-by-wire, each of which typically includes at least one electronic control unit and is often dependent upon data and sensor readings acquired by other electronic systems on-board the vehicle.
The increasing complexity and interaction between various electronic control units in an automotive vehicle has led to the development of advanced in-vehicle communication networks or communication busses which enable the various electronic control units to communicate in a redundant and controlled manner using a common communication protocol. An additional requirement of these in-vehicle communication networks and communication busses is the ability to be fault tolerant in such a way that electronic control units of the various by-wire systems can identify, in real-time, faults or non-functioning components in the vehicle systems. Examples of in-vehicle network communication networks and buses which enable high-speed fault-tolerant communication between various vehicle electronic control units include intrinsically redundant systems such as FlexRay network communication systems and TTP systems, as well as multi-bus systems such as Time Triggered Controller Area Network (TTCAN) systems. Network communication systems utilizing time-division multiple-access protocols, such as Byteflight, are additionally utilized in vehicle applications.
An additional emerging standardization within the automotive industry for in-vehicle electronic systems and communications is identified as the Automotive Open System Architecture (AutoSAR) standard. The AutoSAR standard is based on standardized software interfaces for vehicle electronic components which support the exchangeability of software components within the vehicle electronic components, and which are independent of the specific hardware configuration of the vehicle electronic component. By specifying the software interfaces for vehicle electronic components, the AutoSAR standard enables the use of a standard library of functions and formats for communication and control of individual vehicle electronic components. For example, a first electronic control unit in a vehicle may be configured to access a remote sensor to obtain a measure of vehicle speed. Using the AutoSAR standard, the electronic control unit can then communicate the data value over an in-vehicle communication network or bus to a second electronic control unit such as an engine throttle management controller or a cruise control unit without the need to reformat the data depending upon the specific function of the second electronic control unit.
Other communication busses, which are not necessarily fault-tolerant busses, are utilized in vehicles. For example, the media-oriented systems transport (MOST) bus, and the local interconnect network (LIN) bus are frequently used for user interfaces such as entertainment systems, mirror controls, seat controls, etc. Commands relayed to interconnected vehicle components over these communication busses enable control of vehicle features such as the setting or resetting of service indicator lights, driver warning lights, and other low-priority vehicle functions.
Accordingly, it would be advantageous to provide a vehicle service device, such as a vehicle wheel alignment system, with the necessary components to communicate with one or more vehicle electronic control units and controlled components via the advanced in-vehicle network present in a vehicle undergoing a service procedure, thereby enabling the vehicle service device to extract data from one or more electronic control units, reset control or fault codes in the electronic control units, or to directly control vehicle functions or components as required to complete a vehicle service procedure.